In operation of such an elevator installation it is necessary to take three different braking situations into consideration: holding of the car at a floor stop; retardation of the car in the case of intact support means (also termed emergency stop in the following); and retardation of the car in the case of failure of the support means (termed free-fall braking in the following).
In that case different braking forces must be applied in the different braking situations; thus, for example, for a free-fall braking the braking force must hold the full weight force of the car, for which partial compensation is no longer provided by the counterweight, i.e. the equilibrium. If the brake equipment arrangement comprises two redundant items of brake equipment, then an emergency stop shall also be guaranteed by only one brake equipment, which therefore for reasons of accident safety, for example at a floor stop, consequently has to make available twice the braking force.
If the brake equipment acts with friction couple, the normal forces which the brake equipment must make available also differ in correspondence with the different braking forces. Thus, for example, with a brake equipment arrangement which comprises two items of brake equipment each with two brake circuits a normal force FLNH of at least 6150 N per brake circuit is required for holding the car at a floor stop.FLNH=(rated load/2×g)/(μ×2×2)
FLNH: required holding force for holding the car at standstill with 50% counterweight balancing
rated load: possible loading of the car (example: rated load=1000 kg)
g: gravitational acceleration, 9.81 m/s2 
μ: coefficient of friction (example: μ=0.2)FLNH=(1000/2×g)/(0.2×2×2)=6150 N 
In the case of an emergency stop, with merely one brake equipment now according to requirements a car at a loading of 125% shall, at least, not be further accelerated. In the above example, the required normal force FLNN accordingly increases to:FLNN=(1.5×rated load/2×g)/(μ×2×2)FLNN=(1.5×1000/2×g)/(0.2×1×2)=18600 N. 
For free-fall braking it is further required that the fully laden car shall be safely retarded under the action of all available items of braking equipment. With use of the above example and the assumption that the weight of the empty car is approximately 80% of the rated load and the required minimum retardation of the car is 0.2 g, there results a required normal force FLNF for braking the car of:FLNF=(1.8×useful load×(g+a))/(1×2×2)FLNF=(1.8×1000×1.2 g)/(0.2×2×2)=26500 N 
On the other hand, however, the maximum normal forces required for a free-fall braking should not always act in the different braking situations, since these forces on the one hand strongly load the brake equipment and the rail and on the other hand much energy is required in order to release the brake equipment—which for safety reasons is to automatically apply in the event of failure of the energy supply—during normal travel operation.
Hitherto, therefore, respective individual items of brake equipment were provided for the different braking situations.
Thus, for example, pure braking equipment for braking an elevator car is known from, for example, DE 39 34 492 A1, in which a movable brake lining is displaced by an elevatoring device, or by a movement of the elevator car, on a wedge surface, which then automatically adjusts the movable brake lining under friction couple with the rail. Only by this adjusting movement is a spring stressed, which can counteract an electromagnet in order to regulate the normal force acting on the movable brake lining. This brake equipment is not suitable for holding an elevator car, since it requires a movement of the elevator car for actuation.
EP 1 528 028 A2 describes holding brake equipment in which a reset passive brake lining takes over the function of an active brake lining, which is biased by a compression spring against the rail and which is releasable by an actuator, if this brake lining fails. The brake equipment is for this purpose mounted to be floating. In this brake equipment always the same normal force, which is defined by the spring stress, is exerted on the brake lining when the brake equipment is activated or released. If such brake equipment is to therefore take over not only the holding braking function, but also the emergency stop braking function, this normal force has to be sufficient for braking and is thus over-dimensioned for the normal holding function. Such an over-dimensioned holding normal force, however, disadvantageously loads the brake equipment and the rail and requires a high level of actuator energy for release of the strongly biased spring.